Rush Limbaugh Says Heat Index is a Gov't Conspiracy, Lettermen Mocks Him (Videos) As fringe climate skepticism was being pushed into the cultural mainstream over the last few years, it left many environmentalists and scientists scratching their heads. How could this be happening? we wondered. So we protested, debunked, and screamed facts at the advancing cavalcade of lunacy. But like a cartoony snowball rolling downhill fast, it surely and inexorably gained momentum. That snowball has landed somewhere around here: The nation's most prominent conservative commentator is now denying not only climate change itself, but the mundane, uncontroversial tools that continue to inconveniently provide evidence that it is occurring. Yes, last week, Rush Limbaugh launched into a bizarre rant about how the Heat Index was actually a government conspiracy -- he'll be the judge of what's ho...